Magazine rifle



Dec. 3,- 1929. J. D. PEDERSEN MAGAZINE RIFLE Filed June 9, 192'? 9 Sheets-Sheet 1 IN VEN TOR.

A TTORNEYS.

Dec. 3, 1929.

J. D. PEDERSEN MAGAZINE RIFLE Filed June 9, 1927 9 Sheets-Sheet 2 2 .ATZYORNEYS.

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9 Sheets-Sheet 5 ,2 ATTORNEYS 1929. J. D. PEDERSEN 7 1,737,974

MAGAZINE RIFLE 7 Filed June 9, 1927 9'SheetsSheet. 4

3| 3, 19290 J. o. PEDERSEN 1,737,974

MAGAZINE RIFLE Filed Ju n 9, 192'! 9 Sheets-Sheet s Dec. 3, 1929. PEDERSEN 1,737,974

MAGAZINE RIFLE Filed June 9, 1927 9 Sheets-Sheet 6 BY I . A TTORNEYJ' Dec. 3, 1929. Q

J. D. PEDERSEN MAGAZINE RIFLE Filed June 9, 1927 9 Sheets-Sheet 7 wwmw l Dec.'3, 19290 J. D. PEDERSEIN 1,737,974

MAGAZINE RIFLE Filed June 9, 1927 9 Sheets-Sheet 8 INV NTOR a7 M Al TORNEYJ J. D. PEDERSEN Dec. 3, 1929.

MAGAZINE RIFLE Filed June 9, 1927 9 Sheets-Sheet 9' I ENTOR 4 a 2 ATTORNEYJ but no greater .weig

Patente cc. 3, 12%

JQHN I). PEDERSEN, OF SPRINGFIELD, MASSACHUSETTS MAGAZINE RIFLE Application filed June 9,

This invention relates to improvements in firearms of the automatic type and has for its object a simplified form of construction and organization of parts to secure rapid fire elliciency in a light type of firearm such as a shoulder arm or pistol. The present embodiment of the invention is designed more particularly as an improved military service rifle which will have far reater firing efiiciency it than the magazine service rifles now standard in the principal armies of the world.

The principal features of the invention are applicable to machine guns in general, but

15 for its adaptation to a shoulder rifle the present embodiment is preferably semi-automatic in its action-that is, a separate pull of the trigger is re uiredfor each shot, the loading and cocking eing accomplished automatically. A-further consequence of its use as a shoulder arm is the provision of a magazine for containing a supply of ammunition, preferably in clip en bloc form. Important features of novelty reside in the character of the clip em loyed, which combined with the cartridge eeding and loading mechanism and clip discharge mechanism makes possible an extremely rapid method of firing and recharging.

i A feature of the present rifle which contributes in large degree to its lightness and simplicity of construction lies in the recoll method of operating the automatic mechanism in combination with a fixed barrel. The power for the automatic action is obtained from the rearward pressure of the fired cartridge in the chamber. The cumbersome and more complicated mechanism of a gas operated gun or one with a movable barrel is thus avoided. a

A further feature of importance in the present invention resides in the breech action mechanism which employs the principle of inertia for keeping the breech closed or substantially closed against the explosive force from the fired.cartridge, the parts beingso designed and arranged that said force 1nstigates a very slow opening of the breech so {as to give sufiicient time for the exploding charge to expend itself in discharging the bul- 192'?. Serial N0. 197,71fi.

let before the breech is ciable extent.

In other words, the bolt is not unyieldingly locked to the breech in the usual sensethat is, by any positively acting interengaging locking lugs, but it is in effect locked to the breech by means of inertia and the arrangement of the parts as hereinafter described. Briefly, the arrangement of the parts is such as to transmit directly to the receiver the greater portion of the rearward thrust of the cartridge being fired. Only a relatively small part of the rearward thrust of the cartridge being fired is employed to instigate and effect the opening cycle of the breech mechanism.

The breech mechanism preferably employed is of a. construction somewhat similar to a toggle with one member connected to a longitudinally sliding bolt and the other member connected to the receiver. It is desirable for uniformity of action and consistency of performance in a breech mechanism of this kind that the variations of resistance in the moving parts imposed by frictionall sliding surfaces be minimized. To this en the thrust bearing surfaces of the jointed portions of thetoggle through which the rearward pressure-1s transmitted are designed to partake of a rolling action upon one another as distinguished from an intersliding movement.

One of the principal objects of the invention is to so modify the action of such a toggle breech mechanism by a suitable disposition of connections and shape of abutting surfaces that during a comparatively short distance in the rearward travel of the bolt, as it begins open to any appreto open the breech, the resistance offered to of the principles of operation and objects to be attained in :the present invention, a more detailed description will now be given of a preferred embodiment of the same, from which description further advantages and objects of the invention will become apparent.

Referring briefly to the drawings Fig. 1 is a side elevation of the complete rifle at small scale;

Fig. 2 is a plan view of the gun shown in Fig. 1;

Fig. 3 is a partial sectional elevatlonal view of the receiver taken on a line 3-3 of Fig. 7;

Fig. 3 is a horizontal sectional view through the front end of the bolt taken along the barrel showing the cooling fins thereof;

line 3-3 of Fig. 3;

Fig. .4 is a partial side elevational view of Fig. 5- is a cross section of the barrel along the line 5-5 of Fig. 4 as it would appear when the cover or hand guard of Fig. 6 is assembled on the barrel;

Fig. 6 is a bottom plan view of the cover or hand guard; V

Fig. 7 is a longitudinal section through the receiver with the parts in breech closed position and showing in the magazine chamber an en bloc clip of cartridges in dot-dash lines;

Fig. 8 1s a perspective view of the clip latch;

Fig. 9 is a perspective view of the bolt stop;

Fig. 10 is a fragmentary perspective of the left side of the receiver adj acentthe rear end of the conrod to show how the safety coacts with the receiver;

Fig. 11 is a view similar to Fig. 7 with the parts in position after the firing of the last shot, the clip being discharged and. the bolt in retracted position held by the bolt stop;

Fig. 12 is a rear end view of the cartridge cli with the cartridges en bloc therein;

ig. 13 is a front end view of the same;

Fig. 14 is a plan of the same;

Fig. 15 is a partial plan view of the maga- -zine chamber of the receiver;

Fig. 16 is a longitudinal section through the toggle andbolt in breech closed position; Fig. 17 'is a cross sectional view of the crank and slide taken along line 17-17 of Fig. 16;

Fig. 18 is a similar view with the closing spring locked in compressed condition by the closing spring stop;

Fig. 19 is an inverted planfview of the conrod partly broken away to show the cooking hook and safety;

Fig.20 is a cross sectional view of the conrod taken alon line 2020 of Fig. 19;

Fig. 21 is a etached side view of the sear trip; 4

Fig. 22 is a side view of the bolt detached; Fig. 23' is a rear view of the bolt;

Fig. 24 is a detail of the cockin hook detent detached from its coacting sa ety;

Fig. 25 is a perspective of the link formin part of the articulation between the conro and crank;

Fig. 26 is a sectional elevational view through the receiver showing the inner face of a side wall "thereof;

Figs. 27, 28 and 29 are views somewhat diagrammatic of the toggle in the successive positions assumed during the opening of the breech;

Fig. 30 is a diagram in enlarged scale to illustrate the constant eccentricity of said toggle during the early part of the breech opening movement Fig. 31 is a detail of the articulating surfaces between the conrod and bolt in the position assumed when the breech is partly open;

Fig. 32 is a perspective view of the follower of said feeding mechanism;

Fig. 33 is a rear end view of the rear sight mechanism; 1

Fig. 34 is a top plan view of the same;

Fig. 35 is a vertical section of said rear sight mechanism on line 3535- of Fig. 33

and showing additional parts of the receiver stock and trigger guard frame associated therewith I Fig. 36 is a bottom plan view of a portion of the rear sight slide;

Fig. 37 is a detached view of the sight nut spindle;

Fig. 38 is a detached View of'the sight nut key stem;

Fig. 39 is,a detail cross section through line 3939 of Fig. 26; V v

Fig. 40 is a cross section along line 4040 of Fig. 26; and I Fig 41 is an illustrative view' to show the, difference between the breeching space of the firing chamber and breeching length. of a cartridge.

Referring to ,Fig. 1 of the drawings, the gun of my invention in outward appearance will be seen to resemble closely a standard service rifle and comprises the usual Wooden frame or stock 1, a metal frame or receiver 2, barrel 3, front sight 4, upper band 6, lower band 5, trigger guard 7, and'trigger 8. The rear sight mechanism is indicated generally at 9 and the breech action similarly indicated at 10. A cover 11 for the lower side of the magazine chamber is hinged at its rear end preferably to the trigger guard frame. The upper rear portion ofthe barrel is covered by the hand guard or cover 12.

The barrel 3 is fixed to the receiver 2 and is provided with special means for cooling. In

my preferred embodiment, this consists of a plurality of parallel helically disposed thin fins or flanges 13 which are integral with the barrel and project outwardly therefrom, as shown in Figs. 4 and 5. These helically disposed fins extend entirely around the circumference of the barrel from its rear end to a point adjacent the lower band 5. The advantages of employing such helically dis- .posed fins for cooling purposes are that they impart stiflening strength to the barrel, permit free circulation'of air entirely around the barrel and moreover may be cut out of the barrel stock by a comparatively simple tool operation. a

The cover 12, 'preferably'stamped out of sheet metal, is suitably ribbed for stiffness, with apertures 14 therein (as shown) for lightness and for air circulation. It has a fiat unperforated top 15 running its full length to prevent heat waves from the barrel rising directly in the line of sight and to aid more quickly in catching the front sight of the rifle in aiming. It is mounted so as to be largely spaced from the barrel by the following arrangement. The front end of the cover at 16 (Fig. 6) is reduced in radius so as to seat against the barrel and extend into a counterbore of the lower band 5. The rear edge of the cover is turned down as at 17 so as to engage with an annular groove 17 provided therefor in the barrel and thereby prevent any endwise movement of the cover. The two lateral stiffening ribs 18 and 19 of the cover have inward extensions 20 at the rear ends, 21 about midway of the length and 22 at the front ends thereof. The rearend extensions are arranged to snap with spring tension into mating grooves 20 therefor at each side of the barrel, and thus lock the cover in place after its front end has been inserted beneath the lower band. The extensions 21 and 22 are adapted to bear against the cooling fins of the barrel so as to keep the cover suitably spaced therefrom.

Breech action The breech action is illustrated in Figs. 7 and 11 with certain of the details in other views. It comprises a bolt 23 reciprocable horizontally in the receiver 2 and articulated to a connecting member or conrod 24 which in turn is articulated to a crank 25 having a swinging movement about a crank pin 26 fixed in the receiver. The term conrod is used in this specification as a shortened form of the term connecting rod. The movement of the crank and conrod in opening and closing the breech is somewhat similar to well known toggle mechanism of prior firearms. The action of these parts, however, althou h they are for convenience termed a togg e, differs radically from that of prior structures in man important respects which will be present y pointed out.

The exterior shape of the bolt is shown more clearly in F i 22. It is provided on each side thereof with a laterally projecting rib 27 having a sliding fit in horizontally extending gui ing grooves or tracks, one in each side wall of the receiver, as shown at 28 (see Figs. 11 and 26), to guide the bolt in its longitudinal movement to and from the breech. For the removal of the bolt from the receiver in disassembling, forwardly and upwardly inclined grooves or tracks 29 likewise in the side walls of the receiver communicate with the rear ends of the horizontal tracks 28.

When the crank 25 is out of the way by being first removed from its crank pin 26, the bolt may slide far enough to the rear so that its ribs 27 can be tilted up into the inclined tracks 29 and ermit the bolt to he slid forwardly out of t e receiver.

The conrod 24 is articulated to the bolt in such a manner as to bring the two abutting surfaces 30 and 31 of said respective parts into rolling contact during the early part of the breech opening movement, after which a dolls head pc :tion 32 of the conrod becomes seated in the socket 33 of the bolt for a pivotal engagement during the further opening movement of the breech (see Figs. 27 and 31). This loosely jointed connection between the conrod and the bolt is held from detachment by interengaging male and female portions, viz: a depending lug portion 34 of the conrod is confined'in a recess of the bolt formed by the front wall or surface 31 and a rear wall 35 of the bolt, the upper part of the surface of said rear wall 35 being arcuate to clear a lower curved surface of lug 34 as the conrod swings upwardly. The over-hang of the dolls head socket 33 prevents detachment in a vertical direction and depending side walls 36 of the conrod prevent detachment in a lateral direction. When the conrod and bolt are dismounted from the receiver, the conrod may be swung toward a vertical position far enough to clear the side walls 36 from the wall 35 of the bolt so that a relative lateral movement will then detach the bolt from the conrod.

The articulation between the conrod 24 and the crank is designed to secure a rolling contact between the curved cam surface 37 of the conrod and the curved cam surface 38 of the crank. A connecting link 39 loosely joins these parts (see Fig. 25). It has a laterally projecting gudgeon 40 fitting loosely in a hole 41 of the conrod for limited rotative movement therein. The gudgeon 40 is notched as shown at 42 in Fig. 21 for the purpose of coacting with the sear trip assembl in mutually retaining one another detacha ly in their mounting, as will be later described. A gudgeon 43 is also integral with link 39 and fits for easy rotative movement in a hole 44 of the crank. It is detachably retained therein by an arcuate tenon 45 which takes into an the crank and conrod except when said parts are in a straightened out extension of one another. In this position, provided the crank and conrod are dismounted from the receiver,

' a lateral movement of the link 39 will withdraw the gudgeon 43 from its hole and dis connect the parts. When, however, the parts are mounted in the receiver and are in straightened out extended position, the side Walls of the receiver prevent any lateral displacement between the crank and conrod or etween the conrod and bolt.

The crank is mounted on its crank pin 26 so as to have an initial rolling action, a subsequent pivotal action and a final sliding action thereon. The rear end of the crank has an open ended slot 46 for its bearing on the crank pin 26. The width of this slot 46 is approximately the diameter of the crank pin but its length is somewhat longer as shown. When the crank is down, in breech closed position as shown in Figl 7 the crank pin 26 cccupies the bottom of the slot 46 of the crank. As the crank swings upwardly, the front wall 47 of the slot first rolls and then turns on the crank pin, as shown in the successive positions of Figs. 27, 28 and 11, until the bottom of the slot 46 has moved perceptibly away from the crank pin, as shown in Fig. 11. This view shows the normal position of rest for the parts after the toggle has opened and while the bolt is prevented from closing by the bolt stop later to be described. The bolt,

however, is permitted a further travel to the rear than the position shown in Fig. 11, which additional travel will take place during the recoil after firing. In such a case, the momentum of the bolt carries it back far enough for its rear wall 48 to abut the base 49 of the crank substantially in line with the center of the crank pin 26, a position slightly to the rear of that shown in Fig. 11. It will benoterl also from this view that at the same time the rear lower corner 50 of the conrod will seat into a corner shoulder 51 of the crank and effectively prevent anyfurther swinging tendency of the crank. Thus locked together against further relative movement and as a sort of triangular truss, the bolt, conrod and crank may move rearwardly together as a unit until the bottom of the crank slot 46 abuts against the crank pin 26, as shown in Fig. 29. Simultaneously the back of slide 52 will abut a rear sight support 53 projectingi vertically from the receiver, which together with the crank pin serves as the back stop for finallyarresting the rearward movement of the bolt and toggle. The back stop abutment at 53 is designed to lie approximately on a line with the center'of the moving mass constituting the toggle and bolt so as to arrest their movement with a minimum of strain. A strong bufier action is provided to cushion the shock of this final arresting of the parts breech. A laterally extending finger grip or handle is provided on the slide whereby the crank may be swung upwardly by hand in opening the breech.

The forward end 58 of the Housed in a recess longitudinally of the crank 25 and just beneath the slide 52 is a closing spring 61 mounted on a spring guide 62. The front end of the spring bears against the front endwall 63 of the crank and the rear end of the spring bears through the base of the spring guide 62 against a shoulder 6d of the slide. The tension ofthe spring 61 thus thrusts the slide and its roll against the cam surfaces 56, 57 of the receiver with the resulting reaction of tending to rotate the crank in a clockwise direction. The force of the sprin 61 is suflicient to straighten the toggle an close the breech-with the proper speed of action desired. The slide roll 55 travels on the cam surface 56 during thefirst part of the,

breech closing movement and on the cam surface 57 during the finish of said closing movement. The cam surface 57 is slightly steeper than the surface 56 so as to increase the mechanical advantage of the closing spring 61 as it becomes extended and thus snap the toggle firmly to its final position in closing the breech.

The buffer action for the back stop of the bolt and toggle previously mentioned is afforded by thlS closing spring 61 in coaction with the slide 52 and cam surface 56. Upon firing, the opening movement of the toggle is resisted by the closing spring 61- which is gradually compressed by the slide roll 55 working down on the cam surfaces 57 and 56 until the bolt abuts the crank sli htly to the rear of the position shown in Thereupon the swinging of the crank ceases but the crank, bolt and conrod still travel rearwardly as the crank slidably shifts on its crank pin. This rearward displacement of the crank forces the slide roll 55 upwardly on the cam surface 56 to further compress the closing spring. It will be noted that'the amount of'further compression imparted to the closing sprin bythe rearward sliding of the crank and olt is far greater relatively to the bolt travel than during the openlent of a very powerful buffer spring.

The closing spring tends to maintain the slide at all times with its rear end sufliciently over the crank pin 26 to prevent detachment of the crank. For dismounting the crank from the receiver, the slide is pulled upwardly Fig. 18)

on the crank (when in vertical position as shown in Fig. 11) so as to clear the crank pin. The operation is facilitated by locking the closing spring under compression within the crank so as notto act against the slide. A

closing spring etc 65 (see Figs. 16, 17 and 18) is provided for t is purpose and consists of a s indle rotatively mounted in the crank and having a projecting nose 66 at one side for engaging behind the base of the closing spring guide 62 and a finger piece 67 at the other side. The stop 65 has also a slight endwise movement in its bearings and is normally held forwardly by a spring 68 far enough to prevent any mischance engagement of its nose 66 behind the closing spring guide 62. The spring guide 62 is limited in its forward movement by having its front end abut against the front end wall '63 of the crank so that its base will not pass forwardly of the normal position of projecting nose 66. By pulling the slide 52 upwardly to compress'the closing spring 61 and pushing the stop 65 downwardly against its spring 68 and at the same time rotating said stop slightly, its nose 66 may be engaged behind the guide 62 and thus chain up the closing spring (see The slide may then be easily moved to uncover the crank pin and the crank detached therefrom. One advantage of this construction is that the crank is dismountable without removing the crank pin which may I thus be permanently fixed to the receiver.

Having described somewhat in detail the construction of my preferred form of breech action mechanism, I desire now to point out some of the particular purposes of the construction and the functional effect thereof in the opening and closing of the breech.

The essential requirement of any firearm is that the breech shall be held closed or sufficiently closed for safety during the period of the high pressure in the chamber when fired.

This high firing pressure practically disappears when the bullet leaves the muzzle and is therefore of relatively short duration. It is during this high pressure period thatthe opening of the breech in the present construction is instigated at first very slowly and against a substantially uniform and very high resistance, which uniform resistance outlasts the period of high pressure, after which the opening movement is rapidly completed.

Referring to Fig. 27, which is a view of the present toggle in breech closed osition, the firing pressure is transmitted f i'om the bolt 23 to the conrod 24 through the abutting contact at w, from the conrod to the crank 25 through the abutting contact at y, and from the crank to the crank pin 26 at the contact a. It will be noted that these contact points at, 1 and z are not in astraight line, as would be the case with a true toggle lock. The middle contact 3 is above the line of contact centers a: and 2.- The distance of the contact 3 above said line of contact centers m-z is for convenience termed herein as the eccentricity of the toggle. Due to the eccentricity of the toggle, the firing pressure on the bolt tends to open the toggle. This eccentricity, however, is so small that the greater part of the rearward pressure is transmitted directly to the crank pin 26 and receiver 2 and only a small result of this force acts as a moment of force for opening the toggle. The toggle opens up very slowly under this moment of force and furthermore the parts are so designed that this initial eccentricity of the toggle shall remain substantially constant during the early part of the opening movement and until after the firing pressure has ceased. The bolt 23 of course begins its backward movement upon firing and its distance ofmovement during the period of high firing pressure may be termed the power stroke. The power stroke is necessarily .very short so that no danger of a blow-out from an open breech can-occur. It need only be long enough to instigate the opening of the toggle and store up sufficient energy in the moving parts so that the momentum thereof will complete the full opening. The initial eccentricity of the toggle above mentioned is maintained substantially the same during the aforesaid power stroke of the bolt and preferably for a short time thereafter so as to insure that the rearward movement of saidbolt under the firing pressure shall work against a substantially uniform resistance or load.

The attainment of this result is accomplished by the design and arrangement of the abutting cam surfaces 30, 31, 37 38, 47 and crank pin 26 which serve as bearings for the bolt, conrod and crank. Figs. 27 and 28 show respectively the position of the toggle with the breech closed, and itsv position as it starts to open, which latter position is subsequent to the com 'pletion of the power stroke of the bolt. In Fig. 28, the bolt has moved rearwardly from the points a to b and the intermediate point a in the line ab may be regarded as the rearward end of the power stroke of the bolt, at which point the firing pressure has ceased. It will be observed in Fig. 28 that the initial abutting contact a: between surfaces 31 and 30 has rolled upwardly to m; that the'initial contact 3 (between surfaces 37 and 38) has rolled downwardly to y; and that initial contact a (between the surface 47 and crank pin 26) has rolled upwardly to 2'. Thus although the bolt has moved rearwardly to a point beyond its power stroke and the toggle has begun to fold upwardly, the distance of the contact 3 above the line of contacts :0- 2in other words, the eccentricity of the toggle is no greater than at the start (Fig. 27) This action is perhaps made clearer by reference to the diagrammatic view Fig. 30. Here the lower solid lines represent the relative location of the abutting contacts intend; ed to be illustrated in Fig. 27, and the upper dotted lines the subsequent location of said contacts intended to be shown in Fig. 28. The lines connecting said contacts indicate clearly the toggle eccentricity and its substantial uniformity in the two positions. Of course, no attempt has been made on the drawings to plot any of the distances above mentioned in accurate scale.

During the power stroke of the bolt, the angular movement of the conrod and crank is such that the moment of inertia of the conrod and crank combined with the inertia of the bolt and resistance of the closing sprin almost, but not quite, balance the rearwar thrust of the cartridge on the bolt upon firing. Therefore it is not necessary in the present construction to lock the bolt closed un yieldingly as by the usual positively engaging lugs or shoulders. The present construction possesses the inherently safe closing characteristic of the dead-weight inertia type of breech action in a much more compact and practical form. Under the momentum gained from its start, the toggle continues in itsopening movement through the retracted position of Fig. 11 and thereafter is bodily displaced rearwardly on the crank pin to its rearmost position against the back stop 53, as shown in Fig. 29, after which the closing spring serves to return the parts to breech closed position as previously described.

The rolling cam surfaces 31, 30, 37 38 and 47 provide the additional advantage over true pivotal bearing surfaces of reducing friction, particularly at the start of the toggle opening movement when the firing pressure is being transmitted through said abutting surfaces. A pivot bearin which is in reality a sliding contact woul present the problem of a variable resistance between the limits of a clean oiled surface and a dirty, dry or rust surface, and thus offer greater difliculties 1n the adjustment of a nice balance between the rearward firing pressure and opening resistance-of the toggle, so essential to uniform and consistent operation. After the completion of the power stroke, the avoidance of such frictional variation is not so essential and so the conrod may then swing its dolls head 32 into truepivotal engagement I The bolt and appurtenances A side view ofthe bolt 23 appears inFig. 22, a front view in Fig. 3 and a rear view in Fig. 23. Appurtenant to the bolt and mounted therein are the firing pin 68, firing spring 69, firing spring guide 70, sear 71, extractor 72, and ejector 73. The bolt is a reduced rectangular block with a head portion 23 and tail portion 23", the latter being formed with spaced vertical walls to receive therebetween the sear71 which is pivoted on the sear pivot 74. The space between said vertical walls communicates with a longitudinal recess, circular in cross section, which extends along the bottom of the bolt from an open end at the rear to a closed front end or face of the bolt. Housed in this recess for easy sliding movement'is the firing in 68 of tubular section surrounding the 5 spring guide 70. The firing pin has an ofiset striker and at its rear upper side is a lug 76 forming a sear notch. A lug 77, also integral with upper side of the firing pin, serves as a cocking lug as will be described. The firing spring guide 70 has a head of special formation to fit the rear end of the firing pin recess, said head being bifurcated so as to straddle the tail portion of the bell crank shaped sear 71. The stem of said spring guide 70 extends within the firing sprin and through a front end wall of the tubular pin so as to take into a recess in the back of the bolt face. The spring guide 70 is thus supported at both itsfront and rear ends to insure its alignment and avoid any jamming of the slpring so that a free snappy movement of the ring pin can take place. The firing spring 69 has one end bearing against the base of the spring guide and its other end against the front wall of the tubular firing pin, thus tending to thrust the firing in forwardly and the spring guide rearwar ly (see Fig. 16 showing the parts in firing position). The spring guide base has an upper lug 78 which bears against a shoulder 7 9 on the tail of the sear 71 just below the sear pivot 74 which tends to rotate the sear clockwise and engage the sear nose with the sear notch 76 when the firing pin is in cocked position.

The spring 69 therefore performs the double function of a firing spring and a sear spring. The bifurcated base of the spring guide 70 also extends rearwardly slightly beyond the rear face 48 of the bolt 23 so as to abut the base 49 of the crank just prior to the contact of face 48 therewith in the breech opening movement and thereby move the sprin guide out of contact with the sear shoulder 79 preparatory to the arresting of the bolt. This ring spring 69 and ing the sear is formed with safety lock shoulders 82 which (when the gun is cooked) are adapted to be overlapped by shoulders 83 of a cocking hook ,84 to prevent release of the sear.

This will occur when the saft is manually operated to shift the cooking hook 84 rearwardly from the position shown in Fig. 16. Boththe safety 85 and cocking hook 84 are mounted on the conrod and will be later described in detail in connection therewith.

The extractor 72 is a member slidably mounted for radial movement across the face of the bolt bya T-slot engagement therewith, as shown in Fig. 3. Its forward end is hooked in the usual way to take over the rim of the cartridge. It is yieldingly impelled to its inward position by a spring pressed hollow plunger 86 which encloses a spring 87 and is mounted for longitudinal sliding movement in the head of the bolt. The rear under face of the extractor 7 2 has a tapered recess to receive a conical front end 88 of the plunger 86. The coaction of the conical end 88 with the inclined wall 89 of this recess moves the extractor inwardly on the face of the bolt to its normal position. The outward sliding movement of the extractor is limited by a shoulder 90 of the wall 89 engaging the cylindrical body of the plunger 86. The extractor may be dismounted from the bolt by pressing the plunger 86 backwardly with the point of a cartridge or other tool far enough to clear the front end of the plunger from the shoulder 9!) and at the same time pushing the extractor radially and outwardly of the bolt.

The ejector 73, which tilts the extracted shell and causes its ejection from the gun,

comprises a spring pressed plunger which.

protrudes through the face of the bolt, as shown in Figs. 3, 3 and 31. It is mounted in a recess 91 at one side of the bolt slightly inclined to the horizontal axis of the bolt and with a hearing hole at its rear end to receive the rear end of the plunger 73.. The recess 91 is shorter in length than the ejector plunger 73 and the rear end of the plunger is-tapered to permit of its inclined insertion into said recess. The impelling spring 92 surrounds the plunger and bears against a front collar or shoulder 93 on the plunger, which shoulder lies in the recess 91 and limits the forward i movement of the ejector plunger.

Beneath the front end of the bolt at each U side of its axis are curved tapering cut-outs or clearances 94. These clearances are deepest at the front and as they extend rearwardly gradually merge or disappear in the cylindri-- cally shaped bottom of the bolt. They are for the purpose of facilitating the feeding of the cartridges into position for being loaded. As the bolt moves backwardly over the stack of cartridges in the magazine chamber, which stack is in a double row as hereinafter described, the topmost cartridges being under a feeding pressure from below, is permitted to tilt its pomt upwardly sooner by reason of the clearances 94 and when the bolt finally clears the base of the cartridge the latter has already begun its u wardmovement toward 7 7 loading position. 11 other words, the clearances 94 allow a longer time for the final feeding of each cartridge into position for loading, which is important when the extremely rapid opening and closing movements of the bolt are considered.

On the under side of the bolt, about midway of its length is a pair'of notches 102, one at each side of its central axis, which are adapted to be engaged by the prongs of the bolt stop for holding the bolt in open position under certain circumstances as will be hereinafter described.

The conrod and appurtenances The conrod 24 serves as the connecting rod between the rotating crank and sliding bolt. Mounted within the conrod are the sear trip 81, cocking hook 84 and safety 85. Its front end, as previously described, is confined within an articulating recess of the bolt and integral depending side walls 36 partially embrace-the rear end of the bolt when the conrod is folded down over the same in toggle closed position, as shown in Fig. 7. The cocking hook 84 is formed with a rear extension slid ably mounted beneath the top of the conrod as shown in Figs. 19 and 20. The rear end of the cocking hook passes between the safety 85 and the top of the conrod and its front end passes through a rectangular hole in the depending lug 34 and dolls head 32 of the conrod, whereby it is guided for a limited movement lengthwise of the conrod. The safety 85 is a flat bar mounted transversely of the conrod and extending through bearing holes in each side wall of the conrod. The ends of the safety bar are marked Safe and Ready and either end may be exposed by a transverse shifting of the bar. The upper side of the safety is recessed (as shown in Fig. 19) to I The front face of the wall 97 is formed with positioning notches in which a detent 98 of the cocking hook is adapted to seat and thus locate both the safety 85 and the cocking hook 84 in different positions of adjustment. The detent 98 is abutted by a detent spring guide 100 slidable in the. cocking hook 84 and is im-v pelled by a detent spring 99 housed in the rear end of the cocking hook. The cocking hook also has a limited movement relative to the conrod independently of its'adjustment by the safety, and may retract sli htly within the conrod against the spring 99 uring the cocking operation, as will be described.

The cocking hook 84 performs two functionsone of cocking the firing pin, and one of locking the sear. This latter fimction, which has been previously mentioned, is performed by-a transverse shift of the safety 85 which moves the cocking hook rearwardly and locates the shoulders 83 thereof above the shoulders 82 of the sear 71. The sear nose can then not be released from the sear notch 76 and the gun cannot be fired.

When the toggle is down and the breech is closed, the transverse movement of the safety into safe position carries a rearwardly extended portion 85 of said safety beneath an overhang or shoulder 85" in the side of the receiver wall which will lock the toggle in its down position (see Fig. 10). This insures that when the gun is locked safe, the toggle cannot be raised to lift the hook shoulders 83 off the locking shoulders 82 of the sear. A still further feature of safety is pro vided by the fact that when the cocking hook 84 is shifted to its rear position by the safety 85, the front end of the hook will lie in front of the cooking lug 77 of the firing pin and would thus prevent firing even in the remote contingency of the sear nose 80 or sear notch lug 76 breaking ofi.

- The cocking operation starts with the parts in the position shown in Fig. 16 in which the breech is closed and the firing pin has just been released. The upward swing of the conrod 24 carrying the cockinghook 84 will swing the nose of the latter which is in contact with the cocking lug 77 and retract the firing pin until its sear notch'7 6 is engaged by the sear nose 80. It is desirable that the firing in striker 75 be retracted from the face 0? the bolt promptly with the start of breech opening so that it cannot protrude for any accidental firing of a cartridge with the breech incompletely closed. Due to the special form of articulation between the conrod and the boltwhich, as previously described, causes first' a rolling action of surface 30 on surface 31 and a delayed pivotal action of the dolls head 32 in its socket 33, it has been considered expedient to provide a premature pivotal action for the cooking hook 84 coincidentally with the early rolling action of the conrod. The coeking hook is held yieldingly forward in the conrod by its sprin 101 of the cockinghook will project forwardly of the dolls head 32 and will seat for pivotal action in the dolls head socket 99 so that an upper curved horn hook will-begin its pivotal movement" and start withdrawing the firing pin as soon as the conrod begins to roll upwardly. en the dolls head 32 of the conrod swings into its socket 33, the cocking hook is pressed back into the conrod until its horn 101 coincides with the dolls head 32 and continues its pivotal movement in company with the conrod.

The sear trip 81- comprises a lengthwise bar slidably mounted by a T-slot engage- 'ment in the lower rear -part of the conrod.

When the breech is closed as shown in Fig. 16, the front end of the sear trip is in position to engage the tail of the sear 71 and its rear end with its beveled lower corner 103 is in alignment with a trigger bar 104 (see Fig. 7). The sear trip is moved forwardly to tri the sear by the trigger bar and is provi ed with a return spring 102 housed in a cylindrical plug 105. A stirrup 106 on the front of the sear trip engages behind the head of a spring stem 107 which extends through theplug 105 and has a base 108 for confining the spring 102 within the plug. The plug 105 fits in a cylindrical recess of the conrod directly above and parallel to the slot for the sear trip. The plug is locked in its recess by shoulder 109 of a flat 110 out in the top of the plug, having engagement with the cut out notch 42 in the gudgeon 40, whose transverse hole in the conrod intersects the longitudinal recess of the plug as appears in Fig. 16. The notch 42 extends to the inner end of the gudgeon 40 but the inner end of the notch is made abruptly narrower to form a retaining corner 111 which normally prevents the withdrawal of the gudgeon 40 outwardly from its hole 41 in the conrod. The plug 105, if moved slightly to the rear by a sharp tool as by the point of a cartridge, will clear its shoulder 109 from the retaining corner 111 and. permit the lateral withdrawal of the gudgeon 40. The gudgeon 40 and spring plug 105 mutually lock one another in .-posi the plug with its sear tpip to be withdrawn forwardly from the conrod for the disassembly of these parts.

F im'ng train mechanism.

116 and it is through the swinging of this rocker that the trigger pull is transmitted eventually tothe sear. The upper surface of the arm 114 is preferably contoured in such a way that the engagement of the trigger jaw "33 of thelbolt. By thisaneans the'cocking 113fiherewithwvill produce two distinct tion and the removal of the gudgeon allows trifiger pulls, first a primary or warning P at a relatively long leverage and then the secondary or final pull at a shorter, uicker acting levers. and it is during t is secondary pull t at the sear will release 8the firin 1 r norma rests ainst a spring fiessed plunger* 117, Whi is pressed rearwardly to the position shown in Fig. 7 by a spring 118 housed in the trigger guard 7. The trigger therefore, in addition to its fi stroke rearwardly, may also have a lim ifi forward stroke from its normal position against the plunger 117. The forward stroke of the trigger is employed to release the clip latch in a manner to be described:

The rocker has a forwardly projecting arm 119 adapted to abut a transverse web 120 of the receiver and limit the rocking movement thereof as well as the trigger pull. 7 To 0. depending arm 121 is pivotally connected at 122 the rear end of the trigger bar 104. Below the pivot 122 on arm 121 is pivotally connected at 112' one end of a trigger spring guide 124 which isslidably seated at its other end in a depending lug 126 of the trigger bar. The trigger bar extends forwardly beneath a cross rod 127 fixed in the receiver and upwardly to a beveled nose 104 which normally stands'in position to engage the rear beveled end of the sear trip 103. The trigger spring surrounding the guide 124 tends to swing the tri ger bar upwardly against the cross rod 12 and also to swing the rocker 115 clockwise, and thereby keep the trigger to its normal position against the plunger 117 In other words, the spring 125 serves as a trigger return spring as well as other functions in connection with the trigger bar 104.

A pull of the trigger 8 will swing the rocker 115 counterclockwise and thrust the trigger bar 104 forwardly to operate the sear trip 81, which in turn rocks the sear 71 to release the firing pin. Although the trigger may be held back by a continued pull, the gun will not continue firing automatically because of the-escapement action between the beveled nose 104 of the trigger bar 104 and the beveled rear end 103 of sear trip 81. If the nose 104 is held forward, the subsequent closing of the toggle and breech will bring end 103 down on top'of nose 104 which will cause the trigger bar 104 to yield downwardly against the tension of its spring 125. As soon as the trigger is released, the parts will be restored to the position shown in Fig. 7 with nose 104 ready for a new action. In this way a semi-automatic action for the arm is provided whereby a separate trigger pull is required for each shot.

The engaging lap between the nose 104' of trigger bar 104 and the rear end 103 of the sear trip 81 necessary for firing is made small enough so that said parts will be out of firing coactive relation upon a very slight upward pin. The front of the trig-' or o m'ngmovement of the toggle and preferab be ore the eccentricity 0 said toggle has c anged Pivotally mounted on a pin 129 fixed in the receiver is the bolt stop 130 having rearwardly extending upper pron?0 130" see Fig. 9) adapted to en age the It notc es 102 (see Fig. 22) and old the bolt in open position at certain times. Lower prongs 130" of the bolt stop straddle the trigger bar 104 without interference therewith and are adapted to abuta cross web 131 of the receiver to limit the anti-clockwise movement of the bolt stop.. A lower tail portion 130 of the bolt stop stands behind a rearwardly projecting arm 132 of the clip latch 132 for operation thereby. The bolt stop is normally held in the position shown in F' 7 by the leg 133 of a comparatively light spring coiled about the cross rod 127. Another leg 134 of said same spring presses upwardly against the arm 132 of the clip latch to hold the same in the position shown with its hooked portion 132 in en agement with a nib 135 on the clip 136 an thus serve as a clip restraining means. It is by the clip latch 132 that the clip is retained in the magazine chamber against a force hereinafter described tending to discharge it. The clip latch 132 is pivotally mounted on a pin 137 fixed in the receiver and has a tail portion 132 'ada ted for engagement by the rear lever 163 o the follower mechanism (see Figs. 7 and 11). The arm132 turned lug extending in a side facing recess of the trigger bar 104 so as to be pulled rearwardly thereby when the trigger bar is moved reai wargly from its normal position shown 1n 1 Th5 function of the forward stroke of the trig er 8-will now be evident. Such a forward stroke will, through the trigger bar 104 described, swing the latch 132 to withdraw its hook 132? from the clip 136. The-clip, when thus released, will be discharged upwardly out of the magazine chamber by a clip discharge mechanism com rising a klCker 138 impelled by a powerfhl spring. 'It is desirable not to permit the release of the clip unless the bolt has fully uncovered the magazine chamber and has been withdrawn far enough to be engaged and held by the bolt, stop 130. For this purpose, the crank 25 has a lower'curved surface 139 overlying the top of the trigger jaw 113 which prevents any forward movement of the trigger until the crank has swung vertically far enough to bring a clearance surface 140 above the triggerjaw. When this occurs, the bolt is in position to he engaged b its stop 130 and it will be noted that simu taneously with any release movement of the clip latch 132 its rear arm 132 will engage the tail 130 of the bolt stop 130 and rock it into stoppin engagement with the notches 102 of the olt.

of the clip latch has a laterally This insures loch'ng of the bolt in en .po-.

' sition during any discharge of the c ip and a partially closed bolt.

prevents possible jamming of a clip the latch cannot be released. without swinging the bolt stoplprongs 130 up into the engaging osition in t e notches 102, the accurate timmg of the latch release is provided by the bolt itself which as it moves rearwardly overlies thebolt stop and holds down prongs 130 until the bolt has moved far enough to the rear to bring its notches 102 above the bolt stop, in which position the bolt has fully uncovered the magazine chamber and clip.

The clip discharge mechanism comprises the kicker 138 pivoted on a pin 139' fixed in the trigger guard frame. The kicker carries a plunger 140' bearing against a pin 141 and backed up by a powerful sprmg 142 housed in the kicker and which tends to give the toe of the kicker pressing against the bottom of the cli a quick, owerful, upward thrust. It is su cient to ischarge the clip even full of loaded cartridges completely out of the top of the magazine chamber. The gun may be thus unloaded and rendered harmless at any time by manually withdraw= ing the bolt and pressing the trigger forward.

The pin 141 against which the plunger 140' presses serves as a hinge pin for the bottom cover 11 of the magazine chamber. The forward edge of the cover has a latching engagement with the gun forward of the magazine by means of a lip 144 on the cover adapted to engage a recess in the receiver. The hin e pin 141 is seated in an open slotted. portion of the trigger guard frame so as to permit an endwise movement of the cover against the force of the kicker spring 142. The cover is yieldingly retained in closed latched position bythe tension of the kicker spring and may be unlatched by an endwise movement.

Cartridge clip The cartrid e clip 136, shown in plan Fig. 14, rear view ig. 12, front View Fig. 13 and side view Fig. 7 is designed to'hold a stack of ten cartridges in double row staggered arrangement. The cartridges are preferably .of tapered form and as closely packed in the clip lie with the uppermost cartridge substantially horizontal and the underneath cartridges in positions of progressively greater-inclination as they approach the bottom. The clip is designed to be charged into the magazine chamber with the cartridges en bloc and to serve as a guide and holder of the cartridges during the feeding and loading of the same into the chamber of the bar-' rel. The clip is preferably made of thin spring metal comprising a rigid back 145 and two spring tensioned sides 146, 147 out with Due to the fact that out in places for lightness and suitably stifiened by upset depressions or ribs. It should be noted that the degz'essed ribs 148 on the back are inclined to t c direction of feeding travel for .the cartridges so that the base of the cartridges will not catch or foul therein when being fed upwardly by the follower.

The sides 146, 147 of the clip tend to converge from the back 145 to their front edges so as to furnish lateral spring tension against the stack of cartridges. The bottom of the clip is constituted by the lower front edge prongs 149, 150 which are spring tensioned to press upwardly against the lowermost cartridges of a full stack to furnish vertical tension in holding the same securely and compactly. The tapered form of the cartridges also contributes to this result. Adjacent the rear edge of each side wall is an inwardly projecting rib 151 adapted to engage in front of the extracting rim of the cartridges in each row and in conjunction with the wedgin action of the tapered cartridges in the stack serve to prevent any forward throw of the cartridges under the recoil impulse of firing. The ribs 151 do not extend to the top of the clip so as to leave the top cartrid e free for loading and said ribs do not exten vertically parallel with the back 145 of the clip but diverge therefrom slightly toward the bottom to allow for the increased inclination of the cartridges. The top of the clip is constituted.

portion 154 of the back allows the travel of 1 the bolt therethrough in loading the cartridges. It will be observed that the bolt face will engage the topmost cartridge first from one row and then from the other in loading the same.

On the back of the clip is formed the outwardly ofl'set locking nib 135 which is engageable by the latch 132, as previously described,-for holding the clip in the magazine chamber. The nib 135 is located ofi center or at one side of the center line of the back, and a clearance groove 155 is formed in the rear wall of the magazine chamber (see Fig. 15) to receive this nib 135 when the clip is charged into the magazine. If any attem t is made to insert the clip upside down, t e offset position of the nib will prevent its introduction. Each side of the clip is formed with an inwardly depressed bump 156, 157 which, when the clip is introduced into the magazine chamber, will engage behind ledges 158, 158' provided on each side wall of the chamber, and thereby cause a spreading apart of the clip'sides. In this wa the stack of double row stack into disorder and is to be avoided while the clip is in the gun in order to insure proper feeding of the cartridges.

F eeding means The feeding of the stack of cartridges to bring the uppermost into position for loading is effected by the follower 159 working up through the clip. The follower travels with a definitely prescribed motion so as to conform to the changing positions of inclination of the lowermost cartridges as they are fed upwardly. Both the movement of translation and the movement of partial rotation of the follower are definitely controlled at all times by its actuating and supporting mechanism. In other words, the follower is not free to adjust itself to any inclination of the lowermost cartridges of the stack as is the more common practice. On the contrary, the follower determines its own movement which gives the proper position for the bottom of the stack at all times so that said stack will have no tendency to assume an incorrect position when thrust into the magazine. The follower is designed for contiguous contact with the bottom of the stack at all times and as shown in Fig. 12 is formed with a stepped surface to maintain the staggered arrangement of the two rows of cartridges.

The actuatin means for the follower comprises a sort 0 pantograph arrangement of levers which cause it to sweep upwardly in substantially a straight path through the clip and also gradually change in inclination so as to continuously coincide with the lower most cartridge as it moves eventually into its horizontal osition for loading. The forward one 0 these levers 160 is pivoted at 161 u on the receiver and at 162 to the rear end 0 thefollower. The rear lever 163 is pivoted at 164 on the receiver and has its forward end slidably and pivotally connected to the forward end of the follower 159 by means of a pivot pin 165 fixed to the lever 163 and extending into a slot 166 of the follower. An overhanging lip 167 of the follower overlies the end of the lever 163 to prevent lateral dis lacement thereof. Lever 163 is also cut wit a curved slot 168 within which works the pin 169 carried on lever 160 to thereby connect these levers at their crossing points. The rear lever 163 is the actuating lever for the follower and as shown in Fig 11 is under the tension of a relatively heavy compression spring 17 O which tends to move the follower upwardly at all times. The rear mounting of spring 170 (not shown) is on the cross rod 127 of the receiver.

After the last cartridge has been loaded from the clip and the bolt has moved back to uncover the magazine chamber, the follower 159 may then move to its highest position. As this final movement of the follower takes place, its actuating lever 163 engages the tail portion132 of theclip latch and rocks it to release the empty clip which is then discharged from the chamber by the kicker 138. The follower spring 170 is of course much stronger than the latch spring 134. The release movement of latch 132 also moves the bolt stop 130 into its bolt engaging position, as before described, and therefore the bolt is held back in its position (as shown in Fig. 11) with the magazine chamber open ready for recharging. In other words, the loading and firing of the last cartridge from the clip is automatically followed by the ejection of the empty clip and the stopping of the bolt in open position. \Vhen a new clip is inserted 'in the chamber it of course depresses the follower 159 and restores latch 132 to the force of its spring 134, whereby the new clip will be properly caught and held in the chamber. This recharging operation with a new clip, however, does not automatically release the bolt from its stop 130. Such a result would be undesirable for the person pressing in the new clip and with his fingers part way in the magazine chamber. The strength of the bolt stop restoring spring 133 is insufficient to release the bolt stop from its frictional engagement with the bolt 130-. After the recharging of the clip has been completed, a slight rearward pull by hand on the crank handle 60 will release the bolt stop and the bolt can then be allowed to move forward to closed position under the force of its closing spring. The breech closing movement of the bolt will normally load the top cartridge of the clip into the barrel chamber.

As an additional precaution of safety for the fingers ofthe person charging the magazine with.a new clip, the vertical pressure on a full stack of cartridges provided by the lower prong 149 of the clip is suflicient to prevent the loading of the topmostcartridge out of the clip by the closing movement of the bolt solely under the force of its closing spring. This vertical pressure on the stack is still sufficient for the purpose mentioned even after the sides of the clip have been spread slightly by the ledges 158, 158 as previously described. For the loading of the first cartridge from a full clip, the force of the closing spring must be boosted by hand. After the first cartridge from a full clip has been loaded, the vertical spring pressure of prong 149 has no further effect and the force 

